1. Field of the Invention
New, improved antibiotics are continually in demand. In addition to antibiotics which are useful for human diseases, improved antibiotics are also needed in the veterinary field.
Swine dysentery is a common disease of swine in the United States. It causes great economic losses. The disease is very contagious and can be highly destructive. It is frequently desirable, therefore, to treat even healthy herds which are threatened by outbreaks of the disease.
2. The Prior Art
A-32887 is a polyether antibiotic. At the time parent application Ser. No. 801,876 was filed, A-32887 was thought to be closely related to, but different from, the prior art antibiotic K-41 [J. Antibiotics 29 (1), 10-14 (1976)]. Subsequently, however, it has been determined that A-32887 is identical to K-41. A-32887 (K-41) has the following structure: ##STR1##
K-41 was known to be useful as a Gram-positive antibiotic. The fact that K-41 is useful for the treatment of swine dysentery, however, was not previously recognized.